Mukesh Ambani will be spending around Rs 340 crore on a custom-built Bombardier Global Express XRS — an ultra long-range executive jet that flies just under the speed of sound.

The flying dreamboat can cover up to 12,000 km non-stop or the distance between Mumbai and New York. Touted as one of the latest in business jets, the model was launched this year after test flights in 2005.

The Union government’s aircraft acquisition committee today cleared Reliance Industries’ proposal to buy the aircraft for “private use” — a term used by companies in purchase applications when it is meant for executives.

With a base price of around Rs 250 crore and made by the Canadian company Bombardier Aerospace, the Global Express will function as Mukesh’s “flying office”, sources said.

By the end of 2008, Mukesh can expect to have his jet delivered, which will be loaded with “extras” that top executives “usually prefer”. The total bill could be in the range of Rs 300-340 crore.

The customised plane that Reliance is buying can fly 19 people but will have just eight seats for passengers and a crew complement of four. Mukesh will have a personal room.

All seats will be slumberettes or seats that can be converted into beds. The jet will have a 14.73-metre-long heated and air-conditioned cabin. A noise and vibration cancellation system will ensure quiet in-flight conditions.

Customised interior layouts will include office and conference areas. The baggage compartment at the rear of the cabin will be accessible in-flight.

Industrialists in India used to prefer Beechcraft and Beechking aircraft for their private use. Of late, the Gulfstream IV has also become a favourite.

According to government records, there is only one Bombardier aircraft in India now. But that version (BD 70) is not in the same class as the top-notch Global Express XRS that Mukesh is planning to acquire.

The XRS is said to have already attracted a long list of prospective buyers whose names are being kept confidential by the manufacturer. Oprah Winfrey and Celine Dion are among those who possess the plane now.